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[binutils.git] / gold / archive.cc
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1 // archive.cc -- archive support for gold
3 #include "gold.h"
5 #include <cerrno>
6 #include <cstring>
7 #include <climits>
8 #include <vector>
10 #include "elfcpp.h"
11 #include "fileread.h"
12 #include "readsyms.h"
13 #include "symtab.h"
14 #include "object.h"
15 #include "archive.h"
17 namespace gold
20 // The header of an entry in the archive. This is all readable text,
21 // padded with spaces where necesary. If the contents of an archive
22 // are all text file, the entire archive is readable.
24 struct Archive::Archive_header
26 // The entry name.
27 char ar_name[16];
28 // The file modification time.
29 char ar_date[12];
30 // The user's UID in decimal.
31 char ar_uid[6];
32 // The user's GID in decimal.
33 char ar_gid[6];
34 // The file mode in octal.
35 char ar_mode[8];
36 // The file size in decimal.
37 char ar_size[10];
38 // The final magic code.
39 char ar_fmag[2];
42 // Archive methods.
44 const char Archive::armag[sarmag] =
46 '!', '<', 'a', 'r', 'c', 'h', '>', '\n'
49 const char Archive::arfmag[2] = { '`', '\n' };
51 // Set up the archive: read the symbol map and the extended name
52 // table.
54 void
55 Archive::setup()
57 // The first member of the archive should be the symbol table.
58 std::string armap_name;
59 off_t armap_size = this->read_header(sarmag, &armap_name);
60 off_t off;
61 if (armap_name.empty())
63 this->read_armap(sarmag + sizeof(Archive_header), armap_size);
64 off = sarmag + sizeof(Archive_header) + armap_size;
66 else if (!this->input_file_->options().include_whole_archive())
68 fprintf(stderr, _("%s: %s: no archive symbol table (run ranlib)\n"),
69 program_name, this->name().c_str());
70 gold_exit(false);
72 else
73 off = sarmag;
75 // See if there is an extended name table.
76 if ((off & 1) != 0)
77 ++off;
78 std::string xname;
79 off_t extended_size = this->read_header(off, &xname);
80 if (xname == "/")
82 const unsigned char* p = this->get_view(off + sizeof(Archive_header),
83 extended_size);
84 const char* px = reinterpret_cast<const char*>(p);
85 this->extended_names_.assign(px, extended_size);
88 // Opening the file locked it. Unlock it now.
89 this->input_file_->file().unlock();
92 // Read the archive symbol map.
94 void
95 Archive::read_armap(off_t start, off_t size)
97 // Read in the entire armap.
98 const unsigned char* p = this->get_view(start, size);
100 // Numbers in the armap are always big-endian.
101 const elfcpp::Elf_Word* pword = reinterpret_cast<const elfcpp::Elf_Word*>(p);
102 unsigned int nsyms = elfcpp::Swap<32, true>::readval(pword);
103 ++pword;
105 // Note that the addition is in units of sizeof(elfcpp::Elf_Word).
106 const char* pnames = reinterpret_cast<const char*>(pword + nsyms);
108 this->armap_.resize(nsyms);
110 for (unsigned int i = 0; i < nsyms; ++i)
112 this->armap_[i].name = pnames;
113 this->armap_[i].offset = elfcpp::Swap<32, true>::readval(pword);
114 pnames += strlen(pnames) + 1;
115 ++pword;
118 if (reinterpret_cast<const unsigned char*>(pnames) - p > size)
120 fprintf(stderr, _("%s: %s: bad archive symbol table names\n"),
121 program_name, this->name().c_str());
122 gold_exit(false);
125 // This array keeps track of which symbols are for archive elements
126 // which we have already included in the link.
127 this->seen_.resize(nsyms);
130 // Read the header of an archive member at OFF. Fail if something
131 // goes wrong. Return the size of the member. Set *PNAME to the name
132 // of the member.
134 off_t
135 Archive::read_header(off_t off, std::string* pname)
137 const unsigned char* p = this->get_view(off, sizeof(Archive_header));
138 const Archive_header* hdr = reinterpret_cast<const Archive_header*>(p);
139 return this->interpret_header(hdr, off, pname);
142 // Interpret the header of HDR, the header of the archive member at
143 // file offset OFF. Fail if something goes wrong. Return the size of
144 // the member. Set *PNAME to the name of the member.
146 off_t
147 Archive::interpret_header(const Archive_header* hdr, off_t off,
148 std::string* pname)
150 if (memcmp(hdr->ar_fmag, arfmag, sizeof arfmag) != 0)
152 fprintf(stderr, _("%s; %s: malformed archive header at %ld\n"),
153 program_name, this->name().c_str(),
154 static_cast<long>(off));
155 gold_exit(false);
158 const int size_string_size = sizeof hdr->ar_size;
159 char size_string[size_string_size + 1];
160 memcpy(size_string, hdr->ar_size, size_string_size);
161 char* ps = size_string + size_string_size;
162 while (ps[-1] == ' ')
163 --ps;
164 *ps = '\0';
166 errno = 0;
167 char* end;
168 off_t member_size = strtol(size_string, &end, 10);
169 if (*end != '\0'
170 || member_size < 0
171 || (member_size == LONG_MAX && errno == ERANGE))
173 fprintf(stderr, _("%s: %s: malformed archive header size at %ld\n"),
174 program_name, this->name().c_str(),
175 static_cast<long>(off));
176 gold_exit(false);
179 if (hdr->ar_name[0] != '/')
181 const char* name_end = strchr(hdr->ar_name, '/');
182 if (name_end == NULL
183 || name_end - hdr->ar_name >= static_cast<int>(sizeof hdr->ar_name))
185 fprintf(stderr, _("%s: %s: malformed archive header name at %ld\n"),
186 program_name, this->name().c_str(),
187 static_cast<long>(off));
188 gold_exit(false);
190 pname->assign(hdr->ar_name, name_end - hdr->ar_name);
192 else if (hdr->ar_name[1] == ' ')
194 // This is the symbol table.
195 pname->clear();
197 else if (hdr->ar_name[1] == '/')
199 // This is the extended name table.
200 pname->assign(1, '/');
202 else
204 errno = 0;
205 long x = strtol(hdr->ar_name + 1, &end, 10);
206 if (*end != ' '
207 || x < 0
208 || (x == LONG_MAX && errno == ERANGE)
209 || static_cast<size_t>(x) >= this->extended_names_.size())
211 fprintf(stderr, _("%s: %s: bad extended name index at %ld\n"),
212 program_name, this->name().c_str(),
213 static_cast<long>(off));
214 gold_exit(false);
217 const char* name = this->extended_names_.data() + x;
218 const char* name_end = strchr(name, '/');
219 if (static_cast<size_t>(name_end - name) > this->extended_names_.size()
220 || name_end[1] != '\n')
222 fprintf(stderr, _("%s: %s: bad extended name entry at header %ld\n"),
223 program_name, this->name().c_str(),
224 static_cast<long>(off));
225 gold_exit(false);
227 pname->assign(name, name_end - name);
230 return member_size;
233 // Select members from the archive and add them to the link. We walk
234 // through the elements in the archive map, and look each one up in
235 // the symbol table. If it exists as a strong undefined symbol, we
236 // pull in the corresponding element. We have to do this in a loop,
237 // since pulling in one element may create new undefined symbols which
238 // may be satisfied by other objects in the archive.
240 void
241 Archive::add_symbols(const General_options& options, Symbol_table* symtab,
242 Layout* layout, Input_objects* input_objects)
244 if (this->input_file_->options().include_whole_archive())
245 return this->include_all_members(options, symtab, layout, input_objects);
247 const size_t armap_size = this->armap_.size();
249 bool added_new_object;
252 added_new_object = false;
253 off_t last = -1;
254 for (size_t i = 0; i < armap_size; ++i)
256 if (this->seen_[i])
257 continue;
258 if (this->armap_[i].offset == last)
260 this->seen_[i] = true;
261 continue;
264 Symbol* sym = symtab->lookup(this->armap_[i].name);
265 if (sym == NULL)
266 continue;
267 else if (!sym->is_undefined())
269 this->seen_[i] = true;
270 continue;
272 else if (sym->binding() == elfcpp::STB_WEAK)
273 continue;
275 // We want to include this object in the link.
276 last = this->armap_[i].offset;
277 this->include_member(options, symtab, layout, input_objects, last);
278 this->seen_[i] = true;
279 added_new_object = true;
282 while (added_new_object);
285 // Include all the archive members in the link. This is for --whole-archive.
287 void
288 Archive::include_all_members(const General_options& options,
289 Symbol_table* symtab, Layout* layout,
290 Input_objects* input_objects)
292 off_t off = sarmag;
293 while (true)
295 off_t bytes;
296 const unsigned char* p = this->get_view(off, sizeof(Archive_header),
297 &bytes);
298 if (bytes < sizeof(Archive_header))
300 if (bytes != 0)
302 fprintf(stderr, _("%s: %s: short archive header at %ld\n"),
303 program_name, this->name().c_str(),
304 static_cast<long>(off));
305 gold_exit(false);
308 break;
311 const Archive_header* hdr = reinterpret_cast<const Archive_header*>(p);
312 std::string name;
313 off_t size = this->interpret_header(hdr, off, &name);
314 if (name.empty())
316 // Symbol table.
318 else if (name == "/")
320 // Extended name table.
322 else
323 this->include_member(options, symtab, layout, input_objects, off);
325 off += sizeof(Archive_header) + size;
326 if ((off & 1) != 0)
327 ++off;
331 // Include an archive member in the link. OFF is the file offset of
332 // the member header.
334 void
335 Archive::include_member(const General_options& options, Symbol_table* symtab,
336 Layout* layout, Input_objects* input_objects,
337 off_t off)
339 std::string n;
340 this->read_header(off, &n);
342 size_t memoff = off + sizeof(Archive_header);
344 // Read enough of the file to pick up the entire ELF header.
345 int ehdr_size = elfcpp::Elf_sizes<64>::ehdr_size;
346 off_t bytes;
347 const unsigned char* p = this->input_file_->file().get_view(memoff,
348 ehdr_size,
349 &bytes);
350 if (bytes < 4)
352 fprintf(stderr, _("%s: %s: member at %ld is not an ELF object"),
353 program_name, this->name().c_str(),
354 static_cast<long>(off));
355 gold_exit(false);
358 static unsigned char elfmagic[4] =
360 elfcpp::ELFMAG0, elfcpp::ELFMAG1,
361 elfcpp::ELFMAG2, elfcpp::ELFMAG3
363 if (memcmp(p, elfmagic, 4) != 0)
365 fprintf(stderr, _("%s: %s: member at %ld is not an ELF object"),
366 program_name, this->name().c_str(),
367 static_cast<long>(off));
368 gold_exit(false);
371 Object* obj = make_elf_object((std::string(this->input_file_->filename())
372 + "(" + n + ")"),
373 this->input_file_, memoff, p, bytes);
375 input_objects->add_object(obj);
377 Read_symbols_data sd;
378 obj->read_symbols(&sd);
379 obj->layout(options, symtab, layout, &sd);
380 obj->add_symbols(symtab, &sd);
383 // Add_archive_symbols methods.
385 Add_archive_symbols::~Add_archive_symbols()
387 if (this->this_blocker_ != NULL)
388 delete this->this_blocker_;
389 // next_blocker_ is deleted by the task associated with the next
390 // input file.
393 // Return whether we can add the archive symbols. We are blocked by
394 // this_blocker_. We block next_blocker_. We also lock the file.
396 Task::Is_runnable_type
397 Add_archive_symbols::is_runnable(Workqueue*)
399 if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
400 return IS_BLOCKED;
401 return IS_RUNNABLE;
404 class Add_archive_symbols::Add_archive_symbols_locker : public Task_locker
406 public:
407 Add_archive_symbols_locker(Task_token& token, Workqueue* workqueue,
408 File_read& file)
409 : blocker_(token, workqueue), filelock_(file)
412 private:
413 Task_locker_block blocker_;
414 Task_locker_obj<File_read> filelock_;
417 Task_locker*
418 Add_archive_symbols::locks(Workqueue* workqueue)
420 return new Add_archive_symbols_locker(*this->next_blocker_,
421 workqueue,
422 this->archive_->file());
425 void
426 Add_archive_symbols::run(Workqueue*)
428 this->archive_->add_symbols(this->options_, this->symtab_, this->layout_,
429 this->input_objects_);
431 if (this->input_group_ != NULL)
432 this->input_group_->add_archive(this->archive_);
433 else
435 // We no longer need to know about this archive.
436 delete this->archive_;
440 } // End namespace gold.